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diff --git a/docs/TestSuiteMakefileGuide.rst b/docs/TestSuiteMakefileGuide.rst new file mode 100644 index 0000000000..b10379ef4d --- /dev/null +++ b/docs/TestSuiteMakefileGuide.rst @@ -0,0 +1,279 @@ +============================== +LLVM test-suite Makefile Guide +============================== + +Written by John T. Criswell, Daniel Dunbar, Reid Spencer, and Tanya +Lattner + +.. contents:: + :local: + +Overview +======== + +This document describes the features of the Makefile-based LLVM +test-suite. This way of interacting with the test-suite is deprecated in +favor of running the test-suite using LNT, but may continue to prove +useful for some users. See the Testing Guide's :ref:`test-suite Quickstart +<test-suite-quickstart>` section for more information. + +Test suite Structure +==================== + +The ``test-suite`` module contains a number of programs that can be +compiled with LLVM and executed. These programs are compiled using the +native compiler and various LLVM backends. The output from the program +compiled with the native compiler is assumed correct; the results from +the other programs are compared to the native program output and pass if +they match. + +When executing tests, it is usually a good idea to start out with a +subset of the available tests or programs. This makes test run times +smaller at first and later on this is useful to investigate individual +test failures. To run some test only on a subset of programs, simply +change directory to the programs you want tested and run ``gmake`` +there. Alternatively, you can run a different test using the ``TEST`` +variable to change what tests or run on the selected programs (see below +for more info). + +In addition for testing correctness, the ``test-suite`` directory also +performs timing tests of various LLVM optimizations. It also records +compilation times for the compilers and the JIT. This information can be +used to compare the effectiveness of LLVM's optimizations and code +generation. + +``test-suite`` tests are divided into three types of tests: MultiSource, +SingleSource, and External. + +- ``test-suite/SingleSource`` + + The SingleSource directory contains test programs that are only a + single source file in size. These are usually small benchmark + programs or small programs that calculate a particular value. Several + such programs are grouped together in each directory. + +- ``test-suite/MultiSource`` + + The MultiSource directory contains subdirectories which contain + entire programs with multiple source files. Large benchmarks and + whole applications go here. + +- ``test-suite/External`` + + The External directory contains Makefiles for building code that is + external to (i.e., not distributed with) LLVM. The most prominent + members of this directory are the SPEC 95 and SPEC 2000 benchmark + suites. The ``External`` directory does not contain these actual + tests, but only the Makefiles that know how to properly compile these + programs from somewhere else. The presence and location of these + external programs is configured by the test-suite ``configure`` + script. + +Each tree is then subdivided into several categories, including +applications, benchmarks, regression tests, code that is strange +grammatically, etc. These organizations should be relatively self +explanatory. + +Some tests are known to fail. Some are bugs that we have not fixed yet; +others are features that we haven't added yet (or may never add). In the +regression tests, the result for such tests will be XFAIL (eXpected +FAILure). In this way, you can tell the difference between an expected +and unexpected failure. + +The tests in the test suite have no such feature at this time. If the +test passes, only warnings and other miscellaneous output will be +generated. If a test fails, a large <program> FAILED message will be +displayed. This will help you separate benign warnings from actual test +failures. + +Running the test suite +====================== + +First, all tests are executed within the LLVM object directory tree. +They *are not* executed inside of the LLVM source tree. This is because +the test suite creates temporary files during execution. + +To run the test suite, you need to use the following steps: + +#. ``cd`` into the ``llvm/projects`` directory in your source tree. +#. Check out the ``test-suite`` module with: + + .. code-block:: bash + + % svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite + + This will get the test suite into ``llvm/projects/test-suite``. + +#. Configure and build ``llvm``. + +#. Configure and build ``llvm-gcc``. + +#. Install ``llvm-gcc`` somewhere. + +#. *Re-configure* ``llvm`` from the top level of each build tree (LLVM + object directory tree) in which you want to run the test suite, just + as you do before building LLVM. + + During the *re-configuration*, you must either: (1) have ``llvm-gcc`` + you just built in your path, or (2) specify the directory where your + just-built ``llvm-gcc`` is installed using + ``--with-llvmgccdir=$LLVM_GCC_DIR``. + + You must also tell the configure machinery that the test suite is + available so it can be configured for your build tree: + + .. code-block:: bash + + % cd $LLVM_OBJ_ROOT ; $LLVM_SRC_ROOT/configure [--with-llvmgccdir=$LLVM_GCC_DIR] + + [Remember that ``$LLVM_GCC_DIR`` is the directory where you + *installed* llvm-gcc, not its src or obj directory.] + +#. You can now run the test suite from your build tree as follows: + + .. code-block:: bash + + % cd $LLVM_OBJ_ROOT/projects/test-suite + % make + +Note that the second and third steps only need to be done once. After +you have the suite checked out and configured, you don't need to do it +again (unless the test code or configure script changes). + +Configuring External Tests +-------------------------- + +In order to run the External tests in the ``test-suite`` module, you +must specify *--with-externals*. This must be done during the +*re-configuration* step (see above), and the ``llvm`` re-configuration +must recognize the previously-built ``llvm-gcc``. If any of these is +missing or neglected, the External tests won't work. + +* *--with-externals* + +* *--with-externals=<directory>* + +This tells LLVM where to find any external tests. They are expected to +be in specifically named subdirectories of <``directory``>. If +``directory`` is left unspecified, ``configure`` uses the default value +``/home/vadve/shared/benchmarks/speccpu2000/benchspec``. Subdirectory +names known to LLVM include: + +* spec95 + +* speccpu2000 + +* speccpu2006 + +* povray31 + +Others are added from time to time, and can be determined from +``configure``. + +Running different tests +----------------------- + +In addition to the regular "whole program" tests, the ``test-suite`` +module also provides a mechanism for compiling the programs in different +ways. If the variable TEST is defined on the ``gmake`` command line, the +test system will include a Makefile named +``TEST.<value of TEST variable>.Makefile``. This Makefile can modify +build rules to yield different results. + +For example, the LLVM nightly tester uses ``TEST.nightly.Makefile`` to +create the nightly test reports. To run the nightly tests, run +``gmake TEST=nightly``. + +There are several TEST Makefiles available in the tree. Some of them are +designed for internal LLVM research and will not work outside of the +LLVM research group. They may still be valuable, however, as a guide to +writing your own TEST Makefile for any optimization or analysis passes +that you develop with LLVM. + +Generating test output +---------------------- + +There are a number of ways to run the tests and generate output. The +most simple one is simply running ``gmake`` with no arguments. This will +compile and run all programs in the tree using a number of different +methods and compare results. Any failures are reported in the output, +but are likely drowned in the other output. Passes are not reported +explicitly. + +Somewhat better is running ``gmake TEST=sometest test``, which runs the +specified test and usually adds per-program summaries to the output +(depending on which sometest you use). For example, the ``nightly`` test +explicitly outputs TEST-PASS or TEST-FAIL for every test after each +program. Though these lines are still drowned in the output, it's easy +to grep the output logs in the Output directories. + +Even better are the ``report`` and ``report.format`` targets (where +``format`` is one of ``html``, ``csv``, ``text`` or ``graphs``). The +exact contents of the report are dependent on which ``TEST`` you are +running, but the text results are always shown at the end of the run and +the results are always stored in the ``report.<type>.format`` file (when +running with ``TEST=<type>``). The ``report`` also generate a file +called ``report.<type>.raw.out`` containing the output of the entire +test run. + +Writing custom tests for the test suite +--------------------------------------- + +Assuming you can run the test suite, (e.g. +"``gmake TEST=nightly report``" should work), it is really easy to run +optimizations or code generator components against every program in the +tree, collecting statistics or running custom checks for correctness. At +base, this is how the nightly tester works, it's just one example of a +general framework. + +Lets say that you have an LLVM optimization pass, and you want to see +how many times it triggers. First thing you should do is add an LLVM +`statistic <ProgrammersManual.html#Statistic>`_ to your pass, which will +tally counts of things you care about. + +Following this, you can set up a test and a report that collects these +and formats them for easy viewing. This consists of two files, a +"``test-suite/TEST.XXX.Makefile``" fragment (where XXX is the name of +your test) and a "``test-suite/TEST.XXX.report``" file that indicates +how to format the output into a table. There are many example reports of +various levels of sophistication included with the test suite, and the +framework is very general. + +If you are interested in testing an optimization pass, check out the +"libcalls" test as an example. It can be run like this: + +.. code-block:: bash + + % cd llvm/projects/test-suite/MultiSource/Benchmarks # or some other level + % make TEST=libcalls report + +This will do a bunch of stuff, then eventually print a table like this: + +:: + + Name | total | #exit | + ... + FreeBench/analyzer/analyzer | 51 | 6 | + FreeBench/fourinarow/fourinarow | 1 | 1 | + FreeBench/neural/neural | 19 | 9 | + FreeBench/pifft/pifft | 5 | 3 | + MallocBench/cfrac/cfrac | 1 | * | + MallocBench/espresso/espresso | 52 | 12 | + MallocBench/gs/gs | 4 | * | + Prolangs-C/TimberWolfMC/timberwolfmc | 302 | * | + Prolangs-C/agrep/agrep | 33 | 12 | + Prolangs-C/allroots/allroots | * | * | + Prolangs-C/assembler/assembler | 47 | * | + Prolangs-C/bison/mybison | 74 | * | + ... + +This basically is grepping the -stats output and displaying it in a +table. You can also use the "TEST=libcalls report.html" target to get +the table in HTML form, similarly for report.csv and report.tex. + +The source for this is in ``test-suite/TEST.libcalls.*``. The format is +pretty simple: the Makefile indicates how to run the test (in this case, +"``opt -simplify-libcalls -stats``"), and the report contains one line +for each column of the output. The first value is the header for the +column and the second is the regex to grep the output of the command +for. There are lots of example reports that can do fancy stuff. |